Drilling and tapping machine



Jan. 19, 1937. E. J. STAHLHAMME'R DRILLING AND TAPPING momma* Filed Nov.29, 1933 v8 Sheets-Sheet 1 JQIL 19, 1937- E. J. STAHLHAMMER 2,068,084

DRILLING AND TAPPING MACHINE Filed Nov. 29, 1933 8 Sheets-Sheet 2 |511v. +9 5l -2: r1 f 5954 5 l 'I H Pfg. 2 --174 W II@ y 838k A. '39 I 9o9| (jab H 47 l y 4% r* 9 m 'illo O @x| @o il 54 /I/ O /Q o) .53 l I oO/l l .4Z 43 44 I l i W 4I --f ,o

l Y lg: l 1I I l u 1 I@ 35,- Il l 4 l 3" Ill Ei l "LeM l i ii l 34 39 :EH l 9.15 i l I i l I l `T Ill IZ?. i I: E l5? l) I z5 2/ J; "t n 1 l y i|125 "E 5D l I I I 12ga. l i i` al l l um 5 l ;II I .584 l l I i i l I124 J" 1( l 'Wi VM ei I* "7 II s l. i 'my i l Jan. 19, 1937.

E. J. STAHLHAMMER DRILLING AND TAPPING MACHINE Filed NOV. 29, 1953 8Sheets-Sheet 5 INVENTOR Jan. 19, 1937. E. J. STAHLHAMMER 2,053,034

DRILLING AND TAPPING MACHINE Filed Nov. 29, 195s e sheets-sheet 4 Jan.i9, 1937. E. J. STAHLHAMMER 2,06884 DRILLING AND TAPPING MACHINE A FiledNov. 29, 1953 8 Sheets-Sheet 5 Jan., 19, i937. E. .1. STAHLHAMMER2,068,934

DRILLING AND TAPPING MACHINE Filed Nov. 29, 1933 8 Sheets-Sheet 6 @WNV 1Jan.. i9, 1937. E. .1. STAHLHAMMER.

DRILLING AND TPPING MACHINE Filed NOV. 29, 1935 8 SheS-Sheet 7 Jan. 19,1937. E. J. STAHLHAMMER 2,068,084

DRILLING AND TAPPING MACHINE Filed NOV. 29, 1933 8 Sheets-Sheet 8Patented Jan; 19, 1937 UNITED STATES PATENT OFFICE DRILLING AND TAPPINGMACHINE Eric J. Stahlhammer, Bridgeport, Conn., assignor to The BodineCorporation, Bridgeport, Conn., a corporation of Connecticut ApplicationNovember 29, 1933, Serial No. 700,241

22 Claims.

This invention relates to drilling and tapping machines, especiallymultispindle machines in which a drill or tap operates on one piececarried by one spindle of work while the other 5 tool carried by anotherspindle operates on the same or another piece of work, the work beingusually progressively moved or indexed into position to be engaged bythe tools.

In its more specific aspects, the invention relates to the operation ofsuch a machine hydraulically.

An object of this invention is the provision of a drilling and tappingmachine which is strong and sturdy in construction, so that it mayperform heavy Work, considering its size and weight,

and yet be economically constructed, easily set up and adjusted fordifferent kinds of work, and

reliable in operation.

hereinafter called the f ceding means, and means for progressivelycarrying pieces of work into position to be operated upon by the tools,hereinafter referred to as indexing., and certain other relatedmechanism.

One of the features provision of a reciproc only operates the driv ofthis invention is the ating carriage which` not ing means but alsocontrols the feeding means and the indexing means.

In the disclosed form of the present invention, this carriage comprisesa rack for engaging gears forming part of the driving train, and itcarries cams for controlling the feeding movements of devices forcontrolling the tool. It also carries the indexing mechanism as well asdevices for determining the length of stroke of the carriage.

The carriage is located in an easily reached position, and the cams anddevices above referred to are adjusted on the carriage from the front ofthe machine so that the setting-up of the machine to do a particular jobis comparatively easy.

In the preferred form of the present invention, the carriage is operatedby a fluid-operated motor, and the movements of the carriage are*controlled by a valve operated directly or indirectly `by theadjustable devices, above referred toas being carried by the carriage.

In the preferred Iform of the present invention, hydraulically, trollingthe indexing carriage to be operate by the carriage.

the indexing mechanism is also operated and the valve mechanism forconis located adjacent the d by the devices carried Others of the moreimportant features of this invention comprise the provision of means forregulating the hydraulic pressure applied to the fluid; motor fordriving the rack, the valve mechanism for controlling the fluid motor,the valve mechanism for controlling the indexing, the locking of thework support in adjusted position hydraulically, and the arrangementwhereby locking and indexing mechanism are operated automatically incoordination, and other features and advantages which will hereinafterappear.

In the accompanying drawings- Figure 1 is a side elevation of a drillingand tapping machine made according to the present invention, in itspresent preferred form.

Fig. 2 is a vertical sectional view taken through the middle of themachine shown in Fig. 1.

Fig. 3 is a front elevation of the machine 20 'shown in Fig. 1, with thehood which extends over the driving train shown in section.

Fig. 4 is a vertical sectional view through the upper part of the frame,the carriage, and the valve mechanism for controlling the fluid motor.

Fig. 5 is a front view of the valve actuating mechanism showing the feedcontrol cam, and means for adjustably supporting it on the carriage, theactuating mechanism being in position to move the valve lever.

Fig. 6 is a view similar to Fig. 5, showing the valve lever released andoperated.

Fig. 'l is a front view of the Valve and valve actuating mechanism.

Fig. 8 is a sectional view taken on line 8 8 of Fig. 4, showing thevalve and the fluid operated motor. Fig. 9 isa sectional view of thevalve device for controlling the indexing. Fig. 10 is a verticalsectional view taken on the line I0-I0'of Fig. 9.

Fig. 11 is a vertical sectional view taken on the line II-ll of Fig. 9.

, transmits power from nected to a pump piston for operating theindexing lock plunger.

Fig. 17 is a detail sectional view of the valve shown in Fig. 15.

Fig. 18 is a similar view, looking at the parts from the other side`Fig. 19 is a diagrammatic view showing the manner in which the variousparts of the device are connected together hydraulically.

Fig. 20 is a. sectional view of the pressure regulating valve shown inFig. 19.

Fig. 21 is a sectional shown in Fig. 19.

Fig. 22 is a vertical sectional view through the relief valve employedto avoid the shock and vibration incident to the reversing of thecarriage at the end of its movement toward the right.

As shown in the accompanying drawings, the drilling and tapping machineof the present invention comprises a frame I0 having a base II fromwhich it rises vertically. The frame I0 is hollow and its lower portionconstitutes a reservoir I2 for the fiuid employed to transmit power fromone point on the machine to another. 'Ihe fluid used is preferably anoil, because it not only one point to another on the machine butlubricates the operating parts with which it contacts. Within the hollowframe I0 and mounted on a removable back plate I3 is an electric motorI4 having a drive shaft I5 con- I6 also secured to the removable backplate I3. The pump I6 has an inlet pipe I1 extending down into the oilreservoirv I2 and an outlet pipe I8 connected to the various fluidmotors employed in the operation of the machine.

The casing has a side door which access to the motor may be had foroiling, inspection, etc. By having the motor and pump mounted on theback plate I3, when the latter is removed these parts come out of theframe I0 as a unit.

The front part of the frame I 0 is provided with ways 20 'on which aworktable 2I is slidably mounted and may be secured in desired positionby operation of a clamp 22. To sustain the greater part of the weight ofthe worktable 2|, the frame is provided with a vertical screw 23 havinga handwheel 24 by means of which the frame may be raised and loweredwhen the clamp 22 is released.

'I'he Work, which may be of any desired character, may be fed toposition to be operated upon in any suitable or conventional way, thatis to say, the work may be advanced on a drum, on a I9 by means ofconveyor, or, as shown herein, on a turntable or.

dial 25. The dial or other work lsupport is, of course, provided withsuitable fixtures for holding the work in desired position and it isrotated step-by-step in a manner hereinafter explained to bring piecesof work successively into operating position and progressively from onetool to another.

'I'he `Worktable may be provided with a tray 26 adjustably supported onan extension 21 on which a supply of work to be done may be supported inconvenient position for the operator to insert in the proper places onthe dial 25. As shown, the tray 26 may also be adjusted horizontally,for its depending anges 28 are slidably mounted on a horizontal portion2B of an L-shaped piece 30 and are adjustably secured to the horizontalpiece 29 by screws 3|. 'I'he worktable further has a ldraw 32 forreceiving the chips thrown off by the worktable.

view of the safety valve The working tools T, which may include taps,drills, counterbores, etc., are carried by chucks 33 on spindles 34mounted in bearings 35 having ears 36 which may be clamped to segmentalmounting arms 31 which extend out from a vertically extending auxiliaryframe or slide 38. Bolts 39 secure the spindle bearing arms 36 to theextension 31, and, at the same time, secure arcuate arms 40 to theextensions 31. These arms 4U are employed tosupport other spindles ifand where needed. i

While it is within the scope of this invention to have the work move upand down relative to the tool, in the preferred form of this inventionherein disclosed, the slide 38 carrying the spindles 34 is moved up anddown to feed the tool toward and from the work.- The means foraccomplishing this will be described below.

Tool drive The spindles 34 for the tools T have gears 4I at their upperends. These engage with suitable intermediate gears 42 which ultimatelyengage a gear 43 carried by a shaft 44 having its lower end supported ina bearing 45 carried by the slide 38. The upper end' of the shaft 44engages a bearing 46 carried by the upperportion 41 of the slide 38.Between the bearings 45 and 46, the shaft 44 has a barrel pinion 48which engages with a driving member hereinafter referred to. The upperend 41 of the slide 38 is provided with a post 49 sliding in a bearing50 carried by a bracket 5I attached to the main frame.

As above pointed out, one of the important features of this invention isthe provision of a reciprocating carriage which not only drives thetools but also controls the feeding of the tools and work. Thiscarriage, in the form of the invention herein disclosed, comprises ahorizontal bar 52, a rack 53, a rod 54, and end pieces 55 securing saidrods and rack together in parallel relation. The carriage is guided formovement horizontally in a plane intersecting the axis of the driveshaft 44, and to this end the upper portion of the main frame isAprovided with rollers 56 engaging the rear side of the rack 53. The rod54, as shown in Fig. 8, carries on its center portion a piston 58slidably mounted in a cylinder 59 `of a double-acting uid operated motor60 by means of which the carriage is reciprocated.

The rack 53 engages and drives `the barrel pinion 48 'and the latter ismade long enough so that the driving engagement between the rack and thepinion is maintained even though the pinion travels up and down with theslide 38. The llength of stroke of the carriage and rack determines theamount of rotation of the drive shaft and hence the extent of rotationof the tools T.

The present invention provides means traveling with the carriage C forregulating the stroke of the carriage and determining at l'what pointsin its travel its direction was to be reversed.

According,to the present invention. the adinstable controllers 6| mayoperate any suitable mechanism for causing the carriage to stop at apredetermined point and then reverse its direction oi' travel. However.since, in the embodiment of the invention shown herein, the carriage Cis reciprocated by the double-acting fluid motor 68, the controllers 6|are here employed to operate a stopping and reversing valve 84 (seeFigs. 4 to 8). l

The reversing valve 64 comprising a housing 66 having a manifold 66provided with an inlet pipe 61 and two outlet pipes 68 and 69 adapted tobe connected to opposite ends of the cylinder 59. Within the housingthere is a cylindrical chamber 18 containing a rotary valve 1| havingbearings in the housing 65 and in a cover plate 12 for the housing. Thisrotary valve has a shaft 13 carrying an operating arm 14 which extendsinto position to be engaged and operated by the controllers 6|.

The rotary valve 1| has two deilnite positions in the cylindricalchamber 16 determined by shock absorbing stops 15 mounted on the coverplate 12. The valve 1| has a central channel 16 communicating with twobranches 11 and 18 adapted to alternately communicate with ports 19 and88 of conduits, preferably formed integral with the housing 65 andleading to opposite ends of the cylinder 59.

In addition, the valve 1| has another pair of channels and ports 8| and82 cooperating with the outlet orifices 68 and 69 respectively. In oneposition of the valve, for instance that shown in Fig. 8, the centralport 16 being in communication with the feed pipe or inlet 61 transmitsuid under pressure through the channel i8 to the port 80, and thus-tothe right-hand side of the cylinder 58. At the same time, the channel 8|at the opposite side of the valve is in communication with the outletpipe 68 and also is in communication with the port 19 leading to theleft-hand side of the cylinder, allowing the i'luid therein to escapethrough the outlet pipe 68. When the valve arm 14 is lrocked to move thevalve clockwise 'from the position shown in Fig. 8, the channel 11 isbrought into communication with the port 19, the channel 18 is closed bythe housing 65, and the channel 82 is connected to the port 88, with theresult that fluid under pressure passes through the port 19.

and into the left-hand side of the cylinder and the fluid in theright-hand side escapes through the port and channel 82 to the outletpipe 69, causing the piston 58 and rod 59 to be stopped and then movedto the right.

In order that the carriage C may be stopped and reversed quickly atexactly the right point in its travel, the valve arm 14 is operated,according to the present invention, with a snap action. carries aplunger 83 in position to engage a sleeve 84 on the end of the arm 14and tend to operate it. However, in each of its operating positions, thearm 1d is locked against y movement by a locking pin 85 (see Figs. 4, 5and 6) slidably mounted in the sleeve 84 and springurged to engage alocking piece 86 secured to plunger 83 is being energized, a releasingfinger For this purpose, each controller 6| I8 carried by the controller8| approaches a knob 89 on the locking pin Il. At the proper time, thereleasing ringer begins to withdraw the locking pin 85 from the lockingpiece` 89, and the controller 8| is set so that at just the right momentthe pin 85 will be completely withdrawn and the valve arm 14 will beallowed to move undex the influence of the plunger 88 to the otherposition, the right, as shown in Figs. 5 and 6, with a snap action. Theshock of this rapid movement of the arm 14 is absorbed by theshock-absorbing stops 15, and the locking pin 86 engages the other sideof the locking piece 86 to hold the valve arm 14 in that position.

It-is\o ntemplated by this invention that one of the controllers 6| maybe fixed and incapable of. adjustment, for the adjustment of a singlecontroller will lengtheny or shorten the stroke of the carriage C.However, to permit the points in the travel of the carriage at whichreversing takes place and at which the wear of the rack is maximum to bevaried, it is preferable that both controllers 6| be made adjustablerelative to each other and to the carriage C.

Tool and work feeding According to the'present invention, the carriage Calso controls the feeding movements of the tools. For this`purpose, thepost 49 at thel upper end of the slide 38 is provided with a collar 98having a roller 90 in position to be engaged by cams mounted on andtraveling with the carriage C.

In the form of the invention herein disclosed, there are two cams 92 and93, and these are carried by the controllers 6|. The cam 93 is on theright-hand controller 6| and has a sharp rise which causes or permitsrapid movement oi the slide 38. 'Ihe cam 93 has a pair of slots 94through which extend screws 95. used to secure the cam 93 to thecontroller 6|. These slots 94 extend parallel to the direction of travelof the carriage and permit the cam 93 to be adjusted longitudinally ofthe carriage independently of the controller, so that the point at whichmovement of the slide 38 begins and ends may be varied. This cam 93 isintended to control the movements of the carriage during tappingoperations.

The cam 92, in the form of the invention herein disclosed, forms acontinuation of the cam 93 and is hinged to -it at 96 and has its otherend provided with a vertical slot 91 through which passes a screw 98,(see Fig. 5) by means of which this end of the cam is fastened t0 theleft-hand controller 6|. The vertical slot 91 permits verticaladjustment of the end of the cam 92 and this movement may be regulatedby an adjusting screw 99 carried by the left-hand controller 6|. 'I'hecam 92 is intended to control movements of the slide 38 during thedrilling operation and is designed to regulate the extent of downwardmovement of the slide very accurately, so that a. closed-bottom hole ina workpiece may be tapped just to the proper depth, and so that this maybe done without resetting the position of the tool in the holder orworktable.

It is within the scope of this invention to have the cams 92 and 93actually move the slide i l38 both upwardly and downwardly. However,

regardess of the speed at which the slide 38 descends, 'the presentinvention provides the slide 38 with springs |00 normally tending topull them down. Thus, when the carriage C moves from left to right, theslide 38 is allowed to descend under the influence of the springs |00and at a rate depending upon the inclination of the cams 92 and 93. Onthe return stroke of the carriage, however, that is, when the carriagemoves from right to left, the cams 92 and 93 engage the roller 9|,positively lifting the slide 38 against the tension of the springs |00.

For many purposes, it is suilicent to use the cam 93 alone, and in suchcases the cam is carried solely by, and is adjustable as a unit with,the right-hand controller 6|. Of course, it should be understood thatthe cams 92 and 93 may be given any suitable or desirable shape,depending upon the way that the tools are to be fed to the work, and,since they are removably carried by the controller or the controllers, aseparate cam can be made for each job to be done on the machine.

vAs shown in Figs. 2 and 3, the load on the slide 39 and parts mountedthereon is not borne directly by the rod 52 on which the controller 8|is mounted. Instead, the controller is provided with a rail |0| restingon a roller |02 carried on an arm |03 on the main frame and locateddirectly under the roller 9| on the slide frame 38. Hence, the weight ofthe frame .38 1s transmitted through the cam 93, controller 8| and rail|0| to the roller |02 and the main frame.

It should be noted that in setting up themachine, the mechanic, afterlocating the spindle brackets 35 in desired positions, securing them tothe slide 38, and connecting up the intermecuate gearing, may, whilestill standing in front of the machine, regulate the extent of feed ofthe tool slide 38 by merely reaching up and adjusting the position ofthe cam 93 on the righthand controller 6|. The point in the cycle ofoperations at which the slide 38 begins to movev may be regulated byloosening theclamp 62-63 of the right-hand controller 6| and adjustingit longitudinally along the rod 52. At the same time, if any adjustmentof the position of the worktable 25 is desired, this may belaccomplished by reaching down and turning the handwheel 24. The point atwhich the drive is to be reversed at the end of the downward movement ofthe table 38 may be fixed and determined by loosening the clamp 62-63 onthe left-hand controller 6| and adjusting it along the rod 52 to thedesired position. If it is desired to raise the lower limit of movementof the tool slide 38, the mechanic may merely reach up and adjust theend of the cam 92 by means of the adjusting screw 99.

Thus, according to the present invention, itis unnecessary for themechanic setting up the machine to go around to the back or to the sideof the machine to make adjustments changing the extent or timing of thefeeding operations.

Indexing According to the present invention, the means for moving theworktable 25 step-by-step is also hydraulically operated. This turntable25 is provided with a shaft |04 having an index wheel |05 securedthereto.

Also mounted on the shaft |04 is an arm |06 provided with a pawl |01,the end of which env gages teeth |08 in the index wheel. The pawl isheld in position to enter between the teeth |08 by a spring |09 and thepawl arm is returned to normal position after being operated by a spring||0.

For the purpose of operating the pawl arm and thus moving the turntable25 step-by-step, a cylinder mounted adjacent the index wheel |05 isprovided with a piston ||2 and a piston rod ||3, the end of whichextends out through the cylinder and'is in position to engage the endo1' the pawl arm |06. Instead of directly engaging the arm |06, thepiston rod ||3 engages a screw ||4 adjustably mounted on the end of thearm |06.

The indexing wheel |05 is locked in its p0- sitions of rest by a dog |5which enters between the teeth |08. This dog is on the end of a pistonrod ||6 carrying a piston located in a cylinder H8. As shown in theaccompanying drawings, the cylinders and ||9 are connected together as aunitary structure and are operated' coordinately by hydraulic pressure.

For this purpose, the cylinders and ||8 are connected together by a.pipe or conduit ||9 leading from the lower part of the former to theupper part of the latter as viewed in Fig. 19, and another pipe orconduit |20 leading from the upper part of the cylinder to the lowerpart of the cylinder ||8. This same part of the cylinder I|8 isconnected by pipes |2||22 to an indexing control valve |23, while theconduit or pipe ||9 is connected by pipes |24| 25 to the other side ofthe indexing control valve |23.

Between the pipes |2| and |22, and |24 and |25 are extensibleconnections |22a and |25a respectively, to permit the vertical movementof the worksupport 2| the dial 25 and the indexing lmechanism relativeto the pipes |22 and |25 leading to the control valve |23 which ismounted on the-stationary part or main frame of the machine.

In the broader aspects of this invention, any

suitable control valve may be employed which will cause the fluid underpressure flowing through thepipes |22 and |25 to be reversed in itsdirection of iiow. As diagrammatically illustrated in Fig. 19, themovement of the fluid under pressure is indicated by the arrows, andleaving the valve |23 flows down from the pipes |22 and |2| into thelower part of the cylinder I I8 where it forces the piston and rod ||6outwardly causing the dog ||5 to lock the index wheel |05 againstrotation. The uid then passes through the lower end of the' cylinder ||8into the pipe or conduit |20 and into the upper end of the cylinderwhere it has forced the piston ||2 and piston rod ||3 inwardly of thecylinder allowing the spring ||0 to re tract the pawl arm |06.

In so moving the parts, the uid on the upper side of the piston ||1 andon the lower side of the piston ||2 escapes through the pipe ||9 andpipes |24 and |25 back to the control valve |23.

When the direction of ow is reversed, however, the iluid will flow fromthe valve |23 through the pipes |25-|24 into the pipe or conduit ||9 andfrom this into the upper part of the cylinder ||8 and the lower part ofthe cylinder with the result' that the piston ||1 will move inwardly andwithdraw the locking dog ||5 from the index wheel, and the piston ||2will move outwardly driving the pawl arm to advance the index wheel |05and dial 25. At

the same time, the fluid on the other side of the two pistons, namely,the top of piston ||2 and the bottom of piston ||1, will be permitted toescape through the pipes |20, |2| and |22.

When the valve |23 is reversed at the end of the indexing operation in amanner hereinafter described, it is desired that the locking dog ||5engage the index wheel |05 before the pawl arm |03 begins to return sothat it will not drag the indexvwheel |05 back with it. In order toinsure this, the pipe or conduit |20 is interrupted at some portionbetween the cylinders and H0, and at the interruption is provided with apressure regulating valve |26, .shown in detail in Figs. 17 and 18.

In the specic embodiment of the invention herein disclosed. PSM of theconduit |20 is formed by a channel |21 in the piece making up thecylinder and the regulating valve |26 is located to interrupt thischannel. The valve comprises a movable or plunger portion |28 slid- Aingin a cylinder |29 and normally urged upwardly by a spring |30, the lowerend of which engages an adjustable cap or screw |3|. The upper end ofthe plunger |20 has a knife edge |32 engaging a seat |33 and bleedopenings |34 permit the flow of some fluid past this valve at all times.The spring is set, however, so

, that the full amount of iluid. will not pass through the channel |21until sufllcient presinto the cylinder within which the plunger movesmay escape upwardly and outwardly through the holes |35. I

This coordination of the index wheel lock and feed arm may, of course,be done mechanically, but when accomplished hydraulically, as hereindisclosed, the use of much complicated mechanism is avoided and thefunctions are Vperformed by the simple pressure regulating valve |26. Asstated above, the indexing control valve |23' may be of any suitabletype and construction, and maybe operated in any suitable way.

However, according to the present invention,

the control valve is operated by means carried by the right-handcontroller 5|. For this purpose, the controller 6| is provided withl anextension |36 having an arm |31 carrying a cam |38 (see Figs. 3 and 19),vand the control valve |23 is mounted on the main frame along side thecylinder 59 to be in position to be operated by the cam |33 when thecarriage C reaches the end of its movement toward the left.

As shown in Figs. 9 to 13, the valve |23 has a housing '|39 providedwith a top plate |40 and a bottom plate |4|, and these parts formbetween them cylinder chambers |42 and |43 in which are mounted pistons|44 and |45. The cylinders |44 and |45 are connected together formovement in opposite directions simultaneously by a lever |46, whose endengages in slots |41 in the pistons |44 and |45. The piston |45 isnormally urged downwardly by a spring |48, the upper end of which islocated in a housing |48a.

Thus, the pistons are biased to normally occupy the position shown inFig. 9. The lever |46` is mounted on a shaft |49 which extends outthrough the housing and has an arm |50 provided with a roller |5I.

This roller |5| normally lies in a position to be engaged by the cam |38shown in dot-anddash lines in Fig. 9, and when engaged by the cam isrocked counterclockwise with the result that the piston |44 is depressedand the piston rises against the tension of the spring |48. When the cam|38 recedes from the roller |5I, the spring |48 returns the parts to theposition shown inFig. 9.

The pipes leading to the control valve are arranged in manifold form ina manifold |52, and the conduits in this manifold are given the samereference numerals as the pipes in the diagrammatic illustration of thesystem shown in Fig. 19. Accordingly, the conduit or channel |25 leadsto the cylinder |42, while the conduit or channel |22 leads to thecylinder |43. Between these two channels is another channel |53 whichleads from the control valve |23 to the pipe |8 and pump I6.

Fluid under pressure ilows through the channel |53 and may then ilow tothe right or to the left through an auxiliary channel |54 to the piston|44 or |45. With the parts in the position shown in Figs. 9 to 13 and19, fluid under pressure flows from the channel |54 into an annulargroove |55 in the piston |45, and since this annular groove is incommunication with the channel |22 at this time, fluid flows in thedirection of the arrows shown in Fig. 19. At the same time, a cut-awayportion or port |56 in the piston |44, the lower end of which is hollow,is located opposite the opening of the channel |25, and the fluid risingin the pipe |25, as shown in Fig. 19, ilows into the hollow end of thepiston |44 and then downwardly into a horizontal channel |51 locatedbelow the piston. This channel |51 connects with a channel and pipe |58leading to the reservoir l2.

When the cam |38 engages the roller |5| and rocks the arm and shaft |49and reverses the positions of the pistons from that shown in Fig. 9, thechannel |22 is connectedvto the outlet channel |51 by the hollow cut-outlower portion of the piston |45, and the channel |54 is connected withthe channel |25 by the annular groove in the piston |44, with the resultthat the direction of flow of the fluid is reversed. This causes the dog||5 operated by the piston ||1 to disengage the index wheel |05 afterwhich the feed arm |06 isreturned by the piston H2.

In order to cause the indexing and locking devices to operate beforesuilicient pressure is applied to the driving piston 58 to causemovement thereof, a pressure regulating valve |59 is interposed betweenthe main feed pipe |8 and 'the pipe 61 leading to the valve 64. Thisvalve |59 is illustrated in detail in Fig. 21. It cornprises a housing|60 in which is located a valve |6| having a bleed port |62 allowingsome fluid to escape past the valve at all times. The valve is normallypressed down on its seat by a spring |63 and the upper end of the springis engaged by a screw cap |64 threaded in the housing |60. By rotatingthe screw cap |64, the tension of the spring may be increased ordecreased, thereby determining at what pressure the valve |0| will openand permit passage of the fluid to the pipe 16. A cap |65 threaded 0nthe cap |64 serves to conceal the cap and Fig.`19 and shown in detail inFig'. 22.

acts as a lock nut to prevent its casual movement.

A safety valve |66, constructed substantially the same as the valve |59,is connected to the pipe 16 and has an outlet pipe |61 leading back tothe reservoir I2. Thus, whenv the fluid in the system exceeds thepredetermined pressure, the surplus escapes through the valve |66 andoutlet pipe |61.

When the carriage C is at the end of its movement toward the right andwhile the valve 64 is shifting from one position to another, there is atime when fluid under pressure is applied to both ends of the cylinderand both sides of the piston, with the result that the piston is stoppedwith a hammer blow producing shocks and vibrations which areundesirable. To avoid this diiliculty, the present invention provides arelief valve |68 shown in This relief valve has a housing |69 providedwith a piston-like valve I 10 normally urged downwardly by a spring |1|,the upper end of which engages a perforated wall |12 in the housing. Theend of the valve |10 extends through a gland |13 in position to beoperated by a cam |14 carried by the left-hand controller 6|. The valve|10 has a portion |15 normally closing a port |16 in the housingconnected to a pipe or conduit |11 opening into the pipe 19, leading tothe left-hand side of the cylinder 59. The upper end of the valvehousing |69 is provided with an outlet |18 connected a pipe |19 openinginto a pipe |80 joined to the outlet pipes 68 and 69 which is controlledby the valve 64.

When the carriage reaches its extreme righthand position, the cam |14lifts the valve |10 so that the fluid under pressure in the'pipe |11.may pass into the valve through an annular recess |8| therein. Fluid maythen flow upwardly through small apertures |82 in the valve and throughthe perforated wall |12. Here, however, it is stopped by a pressureregulating valve |83 backed by a spring |84 having an adjustable cap |85and a cover cap |86. The fluid cannot escape past the pressureregulating valve I 83 except when it is under abnormal pressure due tothe fact that the fluid is being applied to both sides of the piston 58.When this abnormal pressure is such that it would cause the piston 58 tobe stopped abruptly, the fluid may escape past the valve |83 into thereturn pipe |80.

Of course, the relief valve |68 may be provided, if desired, for bothends of the pistons travel, but it is not necessary, in the embodimentof the invention herein disclosed, because at the time that the piston58 and carriage C reach the end -of their travel toward the left, theindexing mechanism begins to operate, and this so reduces the pressureof the fluid as to prevent the hammer blow above referred to.

Variations and modifications may be made Within thescope of thisinvention and portions of the improvements may be used Without others. y

Having thus described the invention, what is claimed as new and forwhich it is desired to obtain Letters Patent, is:-

1. In a drilling and tapping machine, the combination of a work-holder;a tool-holder; a tool driving shaft; a pinion on said shaft; a. carriagemounted to reciprocate in a plane intersecting the axis of said shaft; arack on said carriage engaging and driving said pinion; Ie-

' the versible power means connected to said carriage to reciprocate thesame; and means, including means traveling with said carriage, forautomatically reversing the action of the power means at the ends ofvtravel of the carriage.

, 2. In a drilling and tapping machine, the combination of awork-holder; a tool-holder; a tool driving shaft; a lpinion on saidshaft; a carriage mounted to reciprocate in a plane intersecting theaxis of said shaft; a rack on= said carriage engaging and driving saidpinion; reversible power means connected to said carriage to reciprocatethe same; and means, including means traveling with said carriage, forautomatically stopping and reversing the action of the power means atthe ends of travel of the carriage, said last-named means comprisingadjustable devices, one mounted at each sidev of the carriage and eachadjustable along the carriage to vary the points in the travel of the.latter at which its movement isstopped and caused to reverse.

3. In a drilling and tapping machine, the combination of a work-holder;a tool-holder; a tool driving shaft; a pinion on said shaft; a carriagemounted to reciprocate in a plane intersecting the axis of said shaft; arack on said carriage engaging and driving said pinion; means forproducing relative feeding move-v ments of the work-holder andtool-holder toward and from each other, said means including areciprocating slide on which one of said holders is mounted, and a camtraveling with said carriage and engaging said slide to control feedingmovements thereof; reversible power means connected to said carriage toreciprocate the same; and means, including means traveling with saidcarriage, for automatically reversing the action of the power means atthe ends of travel of the carriage.

4.1m a.' drilling and tapping' machine, the combination of awork-holder; a tool-holder; a tool driving shaft; a pinion on saidshaft; a carriage mounted to reciprocate in a `plane intersecting theaxis of said shaft; a rack on said carriage engaging and driving saidpinion;

' means for producing relative feeding movements of the work-holder andtool-holder .toward and from each other, said means including areciprocating slide on which one of said holders is mounted, and a camtraveling with said carriage and engaging said slide to control thefeeding movements thereof, said cam being adjustable along the carriageto vary the relative movements of the tool-holder and the work-holder inrelation to the traveling movements of the carriage; reversible powermeans connected to said carriage to reciprocate the same; and means,including means traveling with said carriage, for automatically stoppingand reversing the action of the power means at the ends of travel of thecarriage, said last-named means comprising adjustable devices, onemounted at each side of the carriage and each adjustable along thecarriage to vary the points in the travel of the latter at which itsmovement is stopped and caused to reverse.

5. In a drilling and tapping machine, the combinationof a frame; atool-holder; a workholder; means for producing relative feedingmovements of the tool-holder and work-holder toward and from each otherincluding a slide on which one of said holders is mounted; a carriagemounted to travel at right angles to the c iiretion` of movement of theslide; a cam on the carriage engaging the slide to control the feedingmovements of the latter; reversible power means connected to saidcarriage to reciprocate the same; and means, including means travelingwith the carriage, for controlling the direction and extent of operationof the carriage.

6. In a drilling and tapping machine, the combination of a frame; atool-holder; a workholder; means for producing relative feedingmovements of the tool-holder and work-holder toward and from each otherincluding a slide on which one of said holders is mounted; a carriagemounted to travel at right angles to the direction of movement of theslide; a cam on the carriage engaging the slide to control the feedingmovements of the latter; a double acting fluid operated motor forreciprocating said carriage; and means, including a reversing valve andoperating means therefor, in part mounted on the carriage and in partmounted on the frame, for controlling the direction and extent ofoperation of the carriage.

7. In a drilling and tapping machine, the combination of a tool-holder;a Work-holder; means for resiliently feeding one of said holders towardthe other to do Work; means for rotating the tool-holder; and a fluidoperated element for simultaneously operating the rotating means andpermitting said resilient feeding means to operate.

8. In a drilling and tapping machine, the combination of a frame; atool-holder; a workholder; means for rotating said tool-holder; meansfor indexing the workholder to bring pieces of work successively intoposition to be operated upon by a tool in the tool-holder; and fluidoperated means for supplying power to and rotating said rotating meansand operating said indexing 'means alternately and in coordination.

9. In a drilling and tapping machine, the combination of a tool-holder;a work-holder; means for feeding one of said holders toward and from theother independently of the rotation of the tool holder; means forrotating said tool-holder; means for indexing the work-holder to bringpieces of work successively into position to be operated upon by a toolin the tool-holder; a fluid motor for supplying power to and operatingsaid feeding means and rotating means simultaneously and incoordination; a separate fiuid motor for operating the indexing meansalternately with said feeding and rotating means; and means forcontrolling said motors for coordinate operation.

10. In a drilling and tapping machine, a reciprocating powertransmitting carriage; a doubleacting fluid motor operating saidcarriage; a source of fluid pressure; a reversing valve connecting thesource of fluid pressure to said fluid motor; an operating arm on saidvalve; means for locking the arm in right and left hand positions;yielding means traveling with the carriage and becoming operative'nearthe end of travel of the carriage to tend to rock said arm; and meanstraveling with the carriage to release the lock suddenly at the end oftravel of the carriage and permit said yielding meansl to rock said armand reverse the direction of drive of the fluid motor and carriage.

11. In a drilling and tapping machine, the combination of a frame; atool-holder; a workholder; means for producing relative feedingmovements of the tool-holder and work-holder toward and from each otherincluding a slide on which one of said holders is mounted; a carriagemounted to travel at right angles lto the direction of movement of theslide: a cam on the carriage engaging the slide to control the feedingmovements of the latter; a double acting `fluid operated motor forreciprocating said carriage; means, including a reversing valve andoperating means therefonin part mounted on the carriage and in partmounted on the frame, for controlling the direction and extent ofoperation of the carriage; and means for relieving the pressure of thefluid onone side of the motor during the reversing operation thereof.

12. In a drilling and tapping machine, the combination of a frame; atool-holder; a workholder; means for producing relative feedingmovements of the tool-holder and work-holder toward and from each otherincluding a slide on whichone of said holders is mounted; a carriagemounted to travel at right angles to the direction of movement of theslide; a cam on the carriage engaging the slide to control the feedingmovements of the latter; a, double acting fluid operated motor forreciprocating said carriage; means, including a reversing valve andoperating means therefor, in part mounted on the carriage and in partmounted on the frame, for controlling the direction and extent ofoperation oi the carriage; and means for relieving the pressure on oneside of the motor during the operation of the reversing valve, saidmeans including a. valve operated by the reciprocating carriage andconnected to the fluid operated motor to bypass the fluid at one side ofthe piston when under excess pressure incidental to the operation of thereversing valve.

13. The invention as defined in claim 5, in which the cam forcontrolling the feeding movements of the slide is adjustablelongitudinally relative to the carriage and to the controlling meansthereon.

14. 'I'he invention as defined in claim 5, in which the cam forcontrolling the feeding movements of the carriage is verticallyadjustable at one end to vary the rate of feeding movements of the sliderelative to the traveling movements of the carriage.

15. The invention as defined in claim 5, in which the cam forcontrolling the feeding movements of the slide is made of two adjustablyconnected parts, one part determining the upper limits of movement ofthe slide andthe other part determining the lower limits of movement ofthe slide.

16. The invention as defined in claim 5, in which the cam forcontrolling the feeding movements of the slide is made of two adjustablyconnected parts, one part determining the upper limits of movement ofthe slide and the other part determining the lower limits of movement ofthe slide, the last-named part being vertically adjustable relative tothe carriage to vary the lower limits of movement of the slide.

17. 'Ihe invention as defined in claim 5, in which the cam forcontrolling the feeding movements of the slide is made of two adjustablyconnected parts, one part determining the upper limits of movement ofthe slide and the other part determining the lower limits of movement ofthe slide, the last-named part being vertically adjustable relative tothe carriage to vary the lower limits of movement of the slide, and thepart which controls the upper limits of movement of the slide beinglongitudinally adjustable relative to the carriage to vary the point inthe operations of the machine at which the slide reaches its upperlimitsof movement.

18. In. a tapping machine, the combination of a Work-hielder; atool-holder; a tool driving shaft; a pinion on said shaft; a carriagemounted to reciprocate in a plane intersecting the' axis of said shaft;a racl; on said carriage engaging and driving said pinion; reversiblepower means connected to said carriage to reciprocate the same; andmeans including means traveling with lsaid carriage, for automaticallyreversing the action of the power means at the ends of travel of thecarriage.

19. In a tapping machine, the 'combination of a work-holder; atool-holder; a tool driving shaft; a pinion on said shaft; a carriagemounted to reciprocate in a plane intersecting the axis of said shaft; arack on said carriage engaging and driving said pinion; reversible powermeans connected to said carriage to reciprocate the same; and means,including means traveling with said carriage, for automatically stoppingand reversing the action of the power means at the ends of travel of thecarriage, said lastnamed means comprising adjustable devices, onemounted at each side of the carriage and each adjustable along thecarriage to vary the points in the travel of the latter at which itsmovement is stopped and caused to reverse.

20. In a tapping machine, the combination of a frame; a tool-holder; awork-holder; means for producing relative feeding; movements of thetool-holder and work-holder toward! and from each other including aslide on which one of said holders is mounted; a carriage mounted totravel at right angles to the direction of movement of the slide; a camon the carriage engaging the slide to control the feeding movements ofthe latter; reversible power means connected to said carriage toreciprocate the same; and means, including means traveling with thecarriage, for controlling the direction and extent of operation of thecarriage.

21. In a tapping machine, the combination of a frame; a tool-holder; awork-holder; means forvrotating said tool-holder; means for indexing thework-holder to bring pieces of work successively into position to beoperated upon by a tool in the tool-holder; and iiuid operated means forsupplying power to and rotating said rotating means and operating saidindexing means alternately and in coordination.

22. In a tapping machine, the combination of a frame; a tool-holder; awork-holder; means for producing relative feeding movements of thetool-holder and work-holder toward and from each other including a slideon which one of said holders is mounted; a carriage mounted to travel lat right angles to the direction of movement of the slide; a cam on thecarriage engaging the slide to control the feeding movements of thelatter; a double acting fluid operated motor for reciprocating saidcarriage; means, including a reversing valve and operating meanstherefor, in. part mounted on the carriage and in part mounted on theframe, for controlling the direction and extent of operation of thecarriage; and means for relieving the pressure of the fluid on one sideof the motor during the reversing operation thereof.

ERIC J. STAHLHAMMER.

